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Proposed new method for the determination of density of soil in place
Studies 29 distinct ez~Ineering ~roperties, including common ~yslcal and mechanical ~roperties obtained in uniaxial, triaxial, Brazilian tensile, and modulus of rupture tests. Also included were Mohr-Coulomb strength parameters. Presents (i) general statistical anl distributional characteristics of some engineering properties, (2) the correlations between various ~operties and several easily obtainable or readily available properties, and (3) several significant bi~-ariate and multiple regression equations which may be used for the prediction of various properties from the easily obtainable or readily available properties.
815033 NOTE ON THE SOURCES OF ACOUSTIC ~MiSSIONS ASSOCIATED WITH SUBCRITICAL C~ACK GR(~l~. TECHT~CAL NCTE Sano, 0 Int J Rock Mech Min Scl, V18, ~3, June 1981 , P259-263 Describes experiments to obtain 2-dlmensiorm.l source locations of the acoustic emissions detected during double torsion testing arg discusses the sources of the acoustic emissions. 81503~ KIC AND J-RESISTANCE-CURVE M/~ASI/R:~NTS ON NEVADA TUFF Weisinger, R; Costin: L S; Lutz, T J Exp Men_h, V20, N2, Feb 1960, P68-72
Texture, structure, composition and density
Linear-elastic fracture mechanics and J-integral test methods were used to determine the static fracture behaviour of a porous volanic tuff. Notched amd prefatigued specimens of two different sizes were tested in three-point bending. The fracture toughness and J-resistance curve for each specimen was determlr~d. The results irzLicate that there is good agre~nent between the fracture parameters determined by the two methods, however there is some dependence of the results on specimen size. Possible reasons for this speclmen-size dependence are discussed.
815O30 IGNITION TEST FOR SOIL ORGANIC-CONTENT Al-~afaJi, A W N; Amiersland, 0 B J Geotech Emgmg Div ASCE, Vl07, NGT4, April
1981, I~%5-~78 Model organic soils prepared frc~ kaolinite and pulp fibres were studied to assess the use of the ignition test for measurement of soil organic content and evaluation of the degree of decomposition. A correction factor for loss of surface hydration water is calculated. A relationahlp between microorganism cell content, umdecomposed organic matter ami the mineral fraction is developed which permits computation of the degree of decomposition.
815035 INFLUENCE OF ORIENTATION ON F R A C I ~ TOUGHNESS AND TENSILE MODULI IN BER~k~Y GRANITE Halleck, P; Ktmunlck, A J Proc 21st US Symposium on Rock Mechanics, Rolla, Missouri, 28-30 May 1980, P235-242
FOR THE D E I ~ E N A T I O N OF 815031 PROPOSED NEW M ~ DENSITY OF SOIL IN PLACE Cernica, J N Geotech Test J, V3, N3, Sept 1980, P120-123 Describes a new method for determining the volume Of soil samples extracted for field density tests. The extracted soll is replaced with sand poured from a graduated cylinder so determining the vOlt~ne of samd; Co,pares the new method to two others approved as AS~4 Stardards: Test fcr Density of Soil in Place by the Samd-cone Method and Test for Density of Soil in Place by the Rubber-balloon Method. The new method yields lower percentage errors amd is less sensitive to edge amd surface irregularities in the sample holes.
Reports 3-point bergirg tests and tensile tests on cylinders and establishes an empirical relationahlp between fracture toughness and tensile moduli. Reports pronounced orientation dependence in both tensile modulus and fracture toughness. Acoustic emission was used to monitor the onset of crack growth. 815036 CALCULATION OF GAS-DRIVEN FRACTURE PROPAGATION IN ROCKS Tray, s, B J; Davis I A H Proc 21st US symposium on Rock Mechanics, Rolla, Missouri, 28-30 May 1980, F356-361 Presents a model for calculating fracture ~ropagation in a porous elastic medium when driven by hot gases. The model determines the sensitivity of fracture propagation to rock permeability and source pressure. The study relates particularly to explosive techniques of gas extraction from shales a~i to containment of underground nuclear explosions.
Fracture processes 815032 SOME MECHANISMS OF MICROCRACM GROWTH AND INTERACTION IN COMPRESSIVE ROCK FAZLURE Dey, T N; Wang, C Y Int J Rock Mech Min Sci, V18, N3, J ~ 1981,
P199-zo9 simple mathematical models based on sc~e experimentally observed ~hencmema are formulated to help tu~ierstamd crack growth, interaction amd rock failure. Graln-sized heterogeneities in rock appear to be ~ in the formation amd growth of mlcrccracks. The interaction of such cracks seems to be responsible for the fcm'm~tlon of an array of en-eehelon cracks extemding diagonally across the r o c k sample ar~ for the coalescence Of these cracks into the final inclined fracture. Together, the proposed models provide an ex~lamation consistent with much of the experimentally observed phenomer~.
815o37
ROLE OF STRESS WAVES AND DISCONTI~KETIES IN ROCK FRA(E4ENTATION: A STUDY OF F R A G M ~ A T I O N IN LARGE LE~STONE ~LOCES Winzer, S R; Ritter, A P Proc 21st US Symposium on Rock Mechanics, Rollaj Missouri, 28-30 May 1980, P362-370 Reports reduced scale blas~img tests in llmestone blocks to study f ~ n t a t i o n under controlled corditions of timing, explosive type a~i borehole geometry. Examination of highspeed motion pictures shows crack formation coincident with the arrival time of the first stress waves at the free-face. Continued fragmeutation of detached pieces is believed to be due to stress waves tral~ped in the block. Pre existing discontint~ties serve as crack initiation sites or re-initiate themselves. 27 refs.
815033 NOTE ON THE SOURCES OF ACOUSTIC ~MiSSIONS ASSOCIATED WITH SUBCRITICAL C~ACK GR(~l~. TECHT~CAL NCTE Sano, 0 Int J Rock Mech Min Scl, V18, ~3, June 1981 , P259-263 Describes experiments to obtain 2-dlmensiorm.l source locations of the acoustic emissions detected during double torsion testing arg discusses the sources of the acoustic emissions. 81503~ KIC AND J-RESISTANCE-CURVE M/~ASI/R:~NTS ON NEVADA TUFF Weisinger, R; Costin: L S; Lutz, T J Exp Men_h, V20, N2, Feb 1960, P68-72
Texture, structure, composition and density
Linear-elastic fracture mechanics and J-integral test methods were used to determine the static fracture behaviour of a porous volanic tuff. Notched amd prefatigued specimens of two different sizes were tested in three-point bending. The fracture toughness and J-resistance curve for each specimen was determlr~d. The results irzLicate that there is good agre~nent between the fracture parameters determined by the two methods, however there is some dependence of the results on specimen size. Possible reasons for this speclmen-size dependence are discussed.
815O30 IGNITION TEST FOR SOIL ORGANIC-CONTENT Al-~afaJi, A W N; Amiersland, 0 B J Geotech Emgmg Div ASCE, Vl07, NGT4, April
1981, I~%5-~78 Model organic soils prepared frc~ kaolinite and pulp fibres were studied to assess the use of the ignition test for measurement of soil organic content and evaluation of the degree of decomposition. A correction factor for loss of surface hydration water is calculated. A relationahlp between microorganism cell content, umdecomposed organic matter ami the mineral fraction is developed which permits computation of the degree of decomposition.
815035 INFLUENCE OF ORIENTATION ON F R A C I ~ TOUGHNESS AND TENSILE MODULI IN BER~k~Y GRANITE Halleck, P; Ktmunlck, A J Proc 21st US Symposium on Rock Mechanics, Rolla, Missouri, 28-30 May 1980, P235-242
FOR THE D E I ~ E N A T I O N OF 815031 PROPOSED NEW M ~ DENSITY OF SOIL IN PLACE Cernica, J N Geotech Test J, V3, N3, Sept 1980, P120-123 Describes a new method for determining the volume Of soil samples extracted for field density tests. The extracted soll is replaced with sand poured from a graduated cylinder so determining the vOlt~ne of samd; Co,pares the new method to two others approved as AS~4 Stardards: Test fcr Density of Soil in Place by the Samd-cone Method and Test for Density of Soil in Place by the Rubber-balloon Method. The new method yields lower percentage errors amd is less sensitive to edge amd surface irregularities in the sample holes.
Reports 3-point bergirg tests and tensile tests on cylinders and establishes an empirical relationahlp between fracture toughness and tensile moduli. Reports pronounced orientation dependence in both tensile modulus and fracture toughness. Acoustic emission was used to monitor the onset of crack growth. 815036 CALCULATION OF GAS-DRIVEN FRACTURE PROPAGATION IN ROCKS Tray, s, B J; Davis I A H Proc 21st US symposium on Rock Mechanics, Rolla, Missouri, 28-30 May 1980, F356-361 Presents a model for calculating fracture ~ropagation in a porous elastic medium when driven by hot gases. The model determines the sensitivity of fracture propagation to rock permeability and source pressure. The study relates particularly to explosive techniques of gas extraction from shales a~i to containment of underground nuclear explosions.
Fracture processes 815032 SOME MECHANISMS OF MICROCRACM GROWTH AND INTERACTION IN COMPRESSIVE ROCK FAZLURE Dey, T N; Wang, C Y Int J Rock Mech Min Sci, V18, N3, J ~ 1981,
P199-zo9 simple mathematical models based on sc~e experimentally observed ~hencmema are formulated to help tu~ierstamd crack growth, interaction amd rock failure. Graln-sized heterogeneities in rock appear to be ~ in the formation amd growth of mlcrccracks. The interaction of such cracks seems to be responsible for the fcm'm~tlon of an array of en-eehelon cracks extemding diagonally across the r o c k sample ar~ for the coalescence Of these cracks into the final inclined fracture. Together, the proposed models provide an ex~lamation consistent with much of the experimentally observed phenomer~.
815o37
ROLE OF STRESS WAVES AND DISCONTI~KETIES IN ROCK FRA(E4ENTATION: A STUDY OF F R A G M ~ A T I O N IN LARGE LE~STONE ~LOCES Winzer, S R; Ritter, A P Proc 21st US Symposium on Rock Mechanics, Rollaj Missouri, 28-30 May 1980, P362-370 Reports reduced scale blas~img tests in llmestone blocks to study f ~ n t a t i o n under controlled corditions of timing, explosive type a~i borehole geometry. Examination of highspeed motion pictures shows crack formation coincident with the arrival time of the first stress waves at the free-face. Continued fragmeutation of detached pieces is believed to be due to stress waves tral~ped in the block. Pre existing discontint~ties serve as crack initiation sites or re-initiate themselves. 27 refs.